Technical Summary
An authenticated/signed attribute is defined to protect the algorithm
definitions of the message body and the signature. Currently this
information is not included in the signature computation and could
theoretically be changed without the signature validator knowing. This
provides an attack avenue on CMS signature and authentication operations
that currently has no known successful attacks. The new attribute is
prophylactic.
Working Group Summary
There was a small amount of discussion on the working group list if this
should be expanded to include the new authenticated encryption
algorithms. It was decided that these should be treated separately by any
interested community. The document was considered in the S/MIME working
group, but there was no push for adoption as it was believed that the
working group would be shutting down shortly.
Document Quality
The document has been implemented by the author and an example of using
the attribute can be found in draft-schaad-smime-hash-experiment. There
are no known plans for vendors to implement this, but I have received
private email asking as to the status of the document.
Personnel
Jim Schaad (ietf@augustcellars.com) is the Document Shepherd.
Sean Turner (turners@ieca.com) is the Responsible Area Director.